HUBBLE SPACE TELESCOPE

   DAILY REPORT #2852

PERIOD COVERED:  0000Z (UTC) 04/16/01 - 0000Z (UTC) 04/17/01

Daily Status Report as of 107/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Five Sets of WF/PC-2 8827 (Cycle 9 Supplemental Darks pt2/3)

        The WF/PC-2 was used to obtain three dark frames every day to 
provide data for monitoring and characterizing the evolution of hot 
pixels.  The proposal completed nominally.

    1.2 Completed Two Sets of STIS/CCD 8864 (CCD Dark Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the darks for the CCD.  The proposal completed nominally.

    1.3 Completed STIS/CCD/MA1 8606 (Determining the Nature of the Variable 
Absorption in AGN: Monitoring NGC 3783 with HST And Chandra)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
investigate Seyfert 1 galaxies, many of which show intrinsic UV absorption 
lines, characterized by high moderate widths, significant outflow 
velocities, and variability on time scales as small as days.  Seyferts with 
UV absorption also show variable X-ray ``warm absorbers'', characterized by 
O VII and O VIII absorption edges, which suggests a common 
origin.  Variability monitoring is the key to understanding the absorbers, 
by providing their radial locations, densities, and evolution in 
ionization, column density, velocity, and coverage of the inner active 
nucleus.  The proposal completed with no problems.

    1.4 Completed Nine Sets of WF/PC-2 9244 (POMS Test Proposal: WFII 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used to perform a generic target version of the 
Archival Pure Parallel program.  The program will be used to take parallel 
images of random areas of the sky, following the recommendations of the 
Parallels Working Group.  The observations completed with no anomalous 
activity.

    1.5 Completed Two Sets of WF/PC-2 8812 (Cycle 9 Internal Monitor)

        The WF/PC-2 was used to obtain routine internal monitors for WFPC2 
in order to monitor the health of the cameras.  A variety of internal 
exposures are obtained in order to provide a monitor of the integrity of 
the CCD camera electronics in both bays {gain 7 and gain 15}, a test for 
quantum efficiency in the CCDs, and a monitor for possible buildup of 
contaminants on the CCD windows.  There were no reported problems.

    1.6 Completed STIS/CCD 8865 (Bias Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1, and 1x1 at 
gain = 4, to build up high-S/N superbiases and track the evolution of hot 
columns.  The proposal completed with no anomalous activity.

    1.7 Completed Two Sets of WF/PC-2 8683 (Imaging Of Brightest Cluster 
Galaxies: The High End Of The Black Hole Mass Distribution)

        The WF/PC-2 was used to make kinematic black hole detections in 
galaxies to decide whether they indicate that the mass correlates with both 
optical luminosity and radio power.  The observation completed with no 
reported problems.

    1.8 Completed Four Sets of STIS/CCD 9248 (Probing the Large Scale 
Structure: Cosmic Shear Observations)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
the distortion of light bundles from distant galaxies that probe the 
statistical properties of the intervening inhomogeneous {dark} matter 
distribution.  Its tidal gravitational field distorts the observable image 
shapes thereby causing a coherent ellipticity pattern {Cosmic Shear}.  The 
observations completed nominally.

    1.9 Completed Two Sets of STIS/CCD 8840 (Read Noise Monitor)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
the read noise of all the amplifiers on the STIS CCD using pairs of bias 
frames.  Full frame and binned observations are made in both Gain 1 and 
Gain 4, with binning factors of 1 x 1, 1 x 2, 2 x 1 and 2 x 2.  All 
exposures are internals.  The observations completed with no reported problems.

    1.10 Completed WF/PC-2 8581 (A Search For Low-Mass Companions To 
Ultracool Dwarfs)

        The WF/PC-2 was used to search for very low-mass {VLM} companions 
to a complete sample of 120 late-M and L dwarfs, drawn mainly from the 
2MASS and SDSS surveys.  The primary goal is to determine the multiplicity 
of M < 0.1 M_odot dwarfs.  In particular, we aim to identify binary systems 
suitable for long-term astrometric monitoring and mass measurement, and 
systems with cool, sub-1000K companions.  The proposal completed with no 
reported problems.

    1.11 Completed Two Sets of STIS/CCD 8607 (Completing the Local AGN 
Inventory: The AGN Content of Composite Nuclei)

        The Space Telescope Imaging Spectrograph (CCD) was used to increase 
the knowledge of the local space density of AGNs which is of fundamental 
importance to a number of astrophysical problems.  A significant fraction 
of nearby galaxies have nuclei whose spectra are intermediate between those 
of LINERs and nuclear starbursts.  These ``transition objects'' may be 
composite systems that contain both a central AGN and circumnuclear star 
formation.  We will test this hypothesis by obtaining spatially-resolved 
optical spectra of a well-defined sample of 15 nearby transition nuclei 
selected from the extensive ground-based survey of Ho, Filippenko, and 
Sargent.  The observations completed with no reported problems.

    1.12 Completed Four Sets of WF/PC-2 8815 (Cycle 9 Earth Flats)

        The WF/PC-2 was used to monitor flatfield stability.  This proposal 
obtains sequences of Earth streak flats to construct high quality flat 
fields for the WF/PC-2 filter set.  These flat fields will allow mapping of 
the OTA illumination pattern and will be used in conjunction with previous 
internal and external flats to generate new pipeline superflats.  The 
proposal completed nominally.

    1.13 Completed Two Sets of WF/PC-2 8824 (Decontaminations and 
Associated Observations Pt. 3/4)

        The WF/PC-2 was used for the monthly WFPC2 decons.  Also included 
are instrument monitors tied to decons: photometric stability check, focus 
monitor, pre- and post-decon internals {bias, intflats, kspots, & darks}, 
UV throughput check, VISFLAT sweep, and internal UV flat check.  There were 
no reported problems.

    1.14 Completed S/C 5582 (FOC/48 Monthly Activation (Camera Section 
Only): Cycle 4)

         This proposal was executed as scheduled, and no anomalies were noted.

    1.15 Completed FOC/96 7923 (FOC F/96 Turn-on)

        The Faint Object Camera (f/96) was used to take an internal flat 
and a dark to ensure that the 30-day limit for the FOC is not 
exceeded.  The observations were executed as scheduled, and no anomalies 
were noted.

    1.16 Completed FGS/1 8774 (Calibrating the Mass-Luminosity Relation at 
the End of the Main Sequence)

        The FGSs-1R was used to calibrate the mass-luminosity relation 
{MLR} for stars less massive than 0.2 Msun, with special emphasis on 
objects near the stellar/brown dwarf border.  Our goals are to determine Mv 
values to 0.10 magnitude, masses to 5%, and more than double the number of 
objects with masses determined to be less than 0.20 Msun.  The proposal 
completed with no reported problems.

    1.17 Completed STIS/CCD/MA1 8712 (The Wind Accretion Wake In A Detached 
Binary System)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
observe RW Hya {= HD 117970}, the only known detached binary system, where 
direct observational evidence for wind accretion onto a white dwarf is 
found.  UV
observations will enable the investigator to advance knowledge in a field 
which has for long had to remain a theoretical subject.  RW Hya is an 
eclipsing system containing a mass-losing M-giant and a hot white dwarf on 
circular orbits {370 days}.  The observation completed with no reported 
problems.

    1.18 Completed STIS/MA1 8843 (Cycle 9 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA1) was used to perform 
the routine monitoring of the MAMA detector dark noise.  The proposal 
completed nominally.

    1.19 Completed STIS/CCD/MA1 8665 (The Starburst - AGN Connection: The 
Nature of the UV-bright Core in NGC 4303)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
observe NGC-4303, to date the best example of the claimed starburst- AGN 
connection in active galaxies.  The observations completed with no reported 
problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  8
Successful:  8

  Scheduled Re-acquisitions:  8
Successful:  8

    2.2 FHST Updates:
Scheduled: 20
Successful: 20

    2.3 Operations Notes:

        The SSR EDAC error counter was cleared three times per ROP SR-1A.

        A TTR was generated when data dropouts occurred, starting at 106/1527Z.

        The ephemeris table was uplinked at 107/0005Z as directed by ROP 
DF-07A.

        The STIS MCE-2 reset at 107/035110Z while the low voltage was on 
and while outside any SAA interval.  The STIS flight software error counter 
was reset at 107/0403Z, using ROP NS-12.  MAMA-2 will be recovered, via 
normal SMS commanding, at 1081740Z when the high voltage is next turned on.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW